I've asked here for information on Mystery Dungeon a month ago, and that got me to buy Explorers of Sky, which I really liked (a lot better than I'd expected from a non-main Pokémon game). I want more Mystery Dungeon, and am interested in maybe getting Gates to Infinity. I've read a little about it, and it seems to be getting mixed opinions. Its main downfall seems to be the lack of playable Pokémon, but honestly, I think I could live with that. In Explorers of Sky, a lot of the storyline wasn't playable with the Pokémon I wanted to bring with me (Absol). I guess I'd be fine using just my character + sidekick if I can't find my favourites in it. But also the story seems to be considered less interesting than Explorers of Sky, and with less post-story content.
So, question is. Is it worth considering buying at all if I've already played Explorers of Sky? Or to those who've played both, is the downgrade too noticeable to enjoy it?